Aircraft power loading system

ABSTRACT

A powered system for moving pallets and containers from a cargo door of an aircraft to a stowed position in an aircraft. The system includes powered rollers to move the pallets or containers laterally from the door into the aircraft and a power unit for moving the containers or pallet longitudinally in the aircraft along a track attached to the aircraft floor or deck. A coupling dolly on which the pallet or container is loaded is operatively associated with the power unit for movement thereby along the track. The dolly includes means to engage the track and means to secure the pallet or container to the dolly of the power unit for movement thereby.

O United States Patent 1 [111 3,756,544 Bader 1 Sept. 4, 1973 [54]AIRCRAFT POWER LOADING SYSTEM I 1,773,087 8/1930 Levin l91/12.2 A [75]In e or: wa E. Ba n o g c 3,099,097 7/1963 Simmons 37/19 Calif PrimaryExaminer-Gerald M. Forlenza [73] Assignee: McDonnell DouglasCorporation, Assistant Examiner-Robert Saifer Mm 7 Santa Monica, Calif.Attorney-Walter J. Jason, George W. Finch et a1.

[22] Filed: Nov. 22, 1971 [57] ABSTRACT 1 1 pp N04 2001935 A poweredsystem for moving pallets and containers from a cargo door of anaircraft to a stowed position in 52 us. Cl 244/137 R, 214/s3.14, 214/84,an elrerefl- The System includes powered rollers to 2145 move thepallets or containers laterally from the door 511 Int. Cl. B64c 1/22into the eirereft and a Power unit for moving the [58] Field of Search214/84, 516, 38 c, miners er pallet longitudinally in the aircraft alonga 214/83.14, 518; l91/l2.2 A; 104/279; ack attached to the aircraftfloor or deck. A coupling 44 R dolly on which the pallet or container isloaded is operatively associated with the power unit for movement [56]References Cited thereby along the track. The dolly includes means toUNITED STATES PATENTS engage the track and means to secure the pallet orcontainer to the dolly of the power unit for movement 2,873,502 2/1959Hodges et al. 214/516 thereby 3,213,993 10/1965 Long 193/35 2,534,05712/1950 Pride 214/65 6 Claims, 5 Drawing Figures 1 AIRCRAFT POWERLOADING SYSTEM BACKGROUND OF THE INVENTION For some time many methods ofloading present and future cargo aircraft have been pursued. Systemssuch as disclosed in U. S. Pat. No. 3,612,316, designed in conjunctionwith new aircraft, have been developed to power cargo modules such aspallets and containers into the aircraft, locate them within theaircraft, and latch them to resist the anticipated loads encountered inflight. The advantages of these systems include improved loading andunloading times, reduced manpower 'and less damage to the aircraft.These systems when designed into new aircraft have no problem withinterference with other systems above or below the floor of theaircraft. However, efforts to install these advanced cargo systems inaircraft whose floors were not designed with cargo systems in mind havemet with failure because of the interference problem.

The end result is that in aircraft currently in use which were notdesigned for power movement of cargo,

- a crew of four or more cargo handlers must be employed to manhandlethe pallets laterally into the aircraft and then longitudinally to theproper station within the aircraft. In some instances, the longitudinalmovement of the pallet assemblies exceeds 100 feet. With normalconditions of the landing gear struts of an aircraft, the tilt on thefloor may exceed 1. When pal lets up to 12,500 lbs. are being pushed upa 1 degree slope, it tends to be a tiring and time consuming operationwhile such pallets being moved in the other direction tend to get awayand damage the aircraft or injure the cargo crew.

SUMMARY OF THE INVENTION The present system is designed to be installedin the floor of existing cargo and cargo convertable aircraft whichusually include omnidirectional movement means such as a ball mat or aplurality of omnidirectional rollers at the door area and rollers ofsome type over which it is possible to move loaded pallets in thelongitudinal direction. The system includes powered rollers installed inthe omnidirectional movement means to enable a single operator to move aloaded pallet from dock side laterally into the aircraft or viceversa.Once the pallet assembly is in the aircraft, a power shuttle assembly isemployed to move it longitudinally to the desired stow position or toremove it to the area where the powered rollers can be employed to movethe pallet out the cargo door.

The power shuttle assembly includes three basic submodules, the firstbeing a track assembly which is connected to the floor of the aircraftto provide guidance and restraint for the shuttle and a means forpositive traction. The track is relatively thin in height so that it canbe installed in an existing aircraft with little or no modificationother than minor revision of the ball mats if they are theomnidirectional means used.

The second submodule is a shuttle dolly that provides the interfacebetween the track assembly and the pallet assembly. The dooly includes aplurality of wheels which support and restrain the dolly to the trackassembly. A plate within the dolly is controllably elevated as desiredto engage the pallet and transfer tractive force thereto. The plate isnormally supported by a pneumatic system so that it can conform toirregularities on the bottom of the pallet assembly while maintaining arelatively large contact area therebetween. Other means for elevatingthe plate can include mechanical or hydraulic systems or combinations ofall three.

The third submodule is the power unit. This unit includes a controllablemotor, a gear drive that engages the rack to the motor, a source ofpneumatic pressure and associated valving and control components. Thepower unit is usually attached to the dolly by means which allow simpleand speedy removal and replacement of the unit.

By using the present system it is possible to reduce the crew requiredto load or unload an aircraft from four or more to one individual whoneed not perform any of the heavy work now required. At the same timethe safety aspects of the cargo loading or unloading operation areenhanced.

It is therefore an object of the present invention to reduce themanpower required to load or unload cargo from an aircraft.

Another object is to provide a power cargo loading system which can beinstalled in existing aircraft with a minimum of aircraft modifications.

Another object is to provide a power cargo loading system which addsonlya minimum of onboard weight to the aircraft.

Another object is to provide a cargo loading system which is simple andsafe to operate.

Another object is to provide a power loadingsystem which can beinstalled in an aircraft at relatively low cost.

Another object is to provide a cargo loading system in which the mostlikely to fail portions thereof can be quickly and easily replacedthereby eliminating the need for standby loading crews.

These and other objects and advantages of the pres ent invention willbecome apparent after considering the following detailed specificationwhich covers a particular embodiment thereof in conjunction with theaccompanying drawings.

BRIEF DESCRIPTION OF THEDRAWINGS DESCRIPTION OF THE SHOWN EMBODIMENTSReferring to the drawings more particularly by reference numbers, number10 in FIG. 1 refers to a power loading system constructed according tothe present invention. The system 10 is shown installed in an aircraftfuselage 12 having a doorway 14, an adjacent ball mat 16 and rollerassemblies 18 to allow the movement of cargo pallets 20 in and out ofthe aircraft. The system 10 includes powered rollers 22 which areenergized by means of a control 24 in the fuselage 12 to enable themovement of the pallets 20 laterally through the doorway 14. Suchpowered rollers 22 and controls 24 therefor are commercially available.The system 10 also includes a power shuttle assembly 26 which is used tomove the cargo pallets 20 longitudinally to predetermined positions inthe fuselage 12 where the pallets 20 can be retained by securing meanssuch as the latch 28.

The power shuttle assembly 26 includes a track 30, a dolly 31 and apower unit 32. The track 30 is mounted in the floor of the fuselage 12and includes, as shown in FIG. 2, an upwardly facing U-shaped portion 33into which the power cable 34 of the power unit 32 extends. The track 30also includes two channel portions 36 and 37 connected by a bottom plate38 which partially surrounds the dolly 31. The dolly 31 is movable onbearings in the form of wheels 40 and 42 which, in concert with thechannel portions 36 and 37, restrain the dolly 31 to only longitudinalmovements along the track 30. The dolly 31 has a raised underside 44 onits main body portion 45 which provides clearance for a linear gear orrack 46 which is attached to the plate 38 between the channel portions36 and 37 of the track 30.

The dolly 31 also includes means to engage pallet assemblies on theopposite ends 47 and 48 thereof. The means on each end include a plate49 having a friction pad 50 thereon which can be lifted into engagementwith the bottom of a pallet 20 thereover by means such as the inflationof an airbag 52. The airbag 52 in a deflated condition is shown in FIG.2 positioned between the main body portion 45 of the dolly 31 and theplate 49. When the airbag 52 is inflated by means to be discussedhereinafter, the plate 49 rises until downwardly facing abutmentsurfaces 54 on the dolly 31 engage upwardly facing abutment surfaces 56on the plate 49. Of course in normal operation the raising of the plate49 is also restricted by the pallet 20 thereon and it is only in thecase where the airbag 52 is inflated when a loaded pallet 20 is notthereover, that the abutment surfaces 54 and 56 normally come intocontact. As shown in FIG. 3, bearing surfaces 58 and 60 on the dolly 31engage end bearing surfaces 62 and 64 on the plate 49 to restrain itfrom anything but vertical movement with respect to the dolly 31.

When it is desired to move a pallet 20 longitudinally in the airplane,the power unit 32 is connected to the dolly 31 by means such as thelatches 68 and the power cord 34 thereof is engaged with an electricalpower supply in the aircraft. When the power unit 32 is placed down ontop of the dolly 31, a pinion gear 70 of the unit 32 extends through anopening 71 in the dolly 31 to engage the rack 46. At the same time,pneumatic connections are completed from the power unit 32 to the dolly31 at ports 72 and 74 thereon for inflation of the airbags 52 and toports 76 and 77 which are connected by lines 78 and 79 respectively tonozzles 80 and 81 at the ends of the dolly 31. The nozzles 80 and 81 areused to blow air across the rack 46 to assure that the track 30 does notbecome clogged with dirt. Once the power unit 32 has been latched to thedolly 31 and is engaged with the rack 46, a lock 82 for holding thedolly 31 at a desired position within the track 30 is released.

The power unit 32 is then operated by means of a pendant control 84which includes a speed control 86, an airbag inflate/deflate control 88and an optional onloff control 90 for the air nozzles 80 and 81. If thepower unit 32 has been completely de-energized since the last operationthereof, the speed control 86 is first manipulated to move the powerunit 32 and the connected dolly 31 back and forth a short distance. Thespeed control 86 is connected by means of an electrical line 92, a plug94 or 95, a control box 96 and a line 98 to a reversable variable speedmotor 100 such as are commercially available from the Breeze Corporationof Union, NJ. The motor 100 is connected through a gear box 102 and atorque limiter 104 to the pinion gear 70. The motor 100 when notenergized maintains the pinion gear 70 stationary. When the motor 100 isenergized in a predetermined direction by the control 86, it causes thepinion gear 70 to drive the power unit 32 and dolly 31 in acorresponding direction.

An air compressor 106 is connected to the gear box 102 and it is drivenby the motor 100 when ever the power unit 32 moves back and forth alongthe track 30. The compressor 106 supplies compressed air through a line108 to an air reservoir 1 10 from which the air can be controllablyconnected to the airbags 52 by an air line 112 in which is included apressure relief valve 114, a filter 116, a pressure regulator 118, asolenoid valve 120 and a manual directional and relief valve 122. Thepower unit 32 need move only a relatively short distance before the aircompressor 106 can sup ply sufficient pressure to inflate an airbag 52.

Once the air pressure has been built up in the air reservoir 110, thepower unit 32 is moved so that one or the other ends 47 or 48 of thedolly 31 are under the pallet 20 to be moved. The handle 124 of thevalve 122 is then moved to point generally in the direction of the end47 or 48 whose airbag 52 is to be inflated. The valve 122 with itshandle positioned as shown in FIG. 4 will enable air to pass through theleft airbag line 126 to inflate the airbag 52 in the end 47 while thehandle position shown in FIG. 1 will allow inflation of the airbag 52 inthe other end 48 by way of the right airbag line 128. The control 88 onthe pendant 84 is then moved to its inflate position which causes anelectrical signal to be sent through lines 92 and 98 to the solenoidvalve 120 which responds by allowing air to flow through the filter 116,the pressure regulator 118 and the valve 122 to inflate the selectedairbag 52.

When the airbag 52 has been inflated, the pad 50 on the associated plate49 engages the underside of the pallet 20 thereover. The speed control86 is then moved so that the power unit 32 and dolly 31 move the pallet20 in the desired direction. During this time should electrical power tothe power unit 32 fail, the solenoid valve 120 is preferably of the typeto either remain in a closed position or move to the inflate position sothe airbag 52 stays inflated to maintain engagement between the shuttle26 and the pallet 20. The motor through release of the speed control 86or upon loss of electrical power, stops moving to thereby restrain thepallet 20 from further movement.

As the power unit 32 and dolly 31 are moving the pallet 20, thereservoir receives a continuing supply of compressed air from thecompressor 106. Once a predetermined pressure has been reached, a valve130 can be opened to allow a restricted flow of air from the reservoir110 and filter 116 through lines 132 and 134 to the nozzles 80 and 81 toblow dirt out of the track 30 as the dolly 31 passes thereover. Thevalve 130 can be operated either by the predetermined pressure orelectrically by means of the optional control 90. If for some reason theair compressor 106 fills the reservoir 1 10 with a predetermined maximumpressure, the relief valve 114 relieves all further pressure increase.

As the power unit 32 moves along the track 30, the power cord 34 thereofis played out or retrieved from the U-shaped portion 33 of the track 30by means of pulleys 136, 138 and 140 and a cable reel 142 which may beof any suitable construction. The cable reel 142 is shown powered fromthe gear box 102 by a flexible drive 144 and a friction clutch 146although other drive means including springs are feasable. The cablereel 142 is used to assure that the power cable 34 is always in apredetermined, tension condition so that it remains within the U-shapedportion 33 of the track 30 and in no case coils up to interfere with theoperation of the power shuttle 26.

When the pallet has been moved to the position desired, the control 88is moved to its deflate position which sends an electrical signal to thesolenoid valve 120, causing it to bleed the air out of the inflatedairbag 52 through the relief port 148 thereof. This causes the pad 50 todisengage the pallet 20 so the dolly 31 can then be moved to a newposition to move another pallet 20.

Once all the pallets 20 have been moved to the desired position by thepower shuttle 26, the power unit 32 can be removed from the aircraft foruse in another aircraft or to reduce the weight of the aircraft. This isdone by turning the handle 124 of the valve 122 until it points to thedownward position which opens a relief port 150 enabling any pressure ineither airbag 52 to escape. If it is desired to completely de-energizethe power unit 32, the control 88 is moved to the inflate position whichenables the air in the reservoir 110 to also vent out through the port150. The lock 82 is then engaged to hold the dolly 31 in the desiredaccessable position and the latches 68 and the power cable 34 aredisconnected to allow the removal of the power unit 32 from the dolly31. It is contemplated that the unit 32 may or may not be removed fromthe aircraft depending on the operational condition encountered inservice and whether any one particular mode of operation proves to bemore advantageous 1 Thus there has been shown and described a novelaircraft power loading system which fulfills all the objects andadvantages sought therefor. Many changes, modifications, variations, andother uses and applications of the subject system will, however, becomeapparent to those skilled in the art after considering the specificationand the accompanying drawings. All such changes,

modifications, alterations and other uses and applications which do notdepart from the spirit and scope of the invention are deemed to becovered by the invention which is limited only by the claims whichfollow.

What is claimed is:

1. A system for moving cargo in an aircraft having a roller floor, saidsystem including a power shuttle assembly comprised of:

a track assembly positioned longitudinally in the roller floor of theaircraft including a rack;

a dolly assembly adapted to be movable along said track assembly, saiddolly assembly including means for predeterminately, frictionallyengaging beneath the cargo which include a plate member restrained tolimited vertical movement with respect to said dolly assembly, anupwardly facing friction pad on said plate member, and an airbag inposition beneath said plate member to raise said plate member and saidfriction pad when inflated; and

a power unit including means for removable attachment to said dollyassembly including means for establishing pneumatic communicationtherebetween, a pinion gear for positive engagement with said trackassembly rack, a reversable variable speed electric motor, an electricalpower cable for conducting electrical energy to said electric motor,means to transfer torque between said pinion gear and said electricmotor so that said electric motor can drive said power unit with respectto the aircraft so said dolly assembly can be controllably moved alongsaid track assembly, means to maintain a predetermined tension on saidpower cable as said power unit moves with respect to the aircraft, meansfor supplying pressurized gas, and valve means, said valve meansincluding a solenoid valve having an inlet port connected to said supplymeans, an outlet port for connection to said airbag and a vent port,said solenoid valve when energized being capable of controllably openinga passageway between said inlet port and said outlet port, andcontrollably opening a passageway between said outlet port and said ventport, said solenoid closing said outlet port when de-energized. pg,16

2. The system defined in claim 1 wherein said dolly assembly includes:

opposite end portions, each end including said frictional means forextending under the cargo and for controllably'frictionally engagingtherewith; and

a central portion between said opposite end portions adapted forengagement with said power unit.

3. The system defined in claim 2 wherein said valve means include:

a manual valve connected to said solenoid valve output port, said manualvalve having a first position for opening a passageway from saidsolenoid valve output port to said frictional means in one of saidopposite end portions, and a second position for opening a passagewayfrom said solenoid valve output port to said frictional means in theother of said opposite end portions.

4. The system defined in claim 1 including:

powered rollers positioned in the floor of the aircraft and spaced fromsaid track assembly;

control means for said powered rollers whereby said powered rollers canbe used to move cargo at generally right angles to said track assemblyto facilitate lateral movement of the cargo within the aircraft.

5. The system defined in claim 1 including:

a remote control device; and

an electrical cable for connecting said remote control device to saidpower unit so that the operation of said control unit can be controlledthereby, said remote control device including a directional speedcontrol for said motor and a solenoid valve control.

6. The system defined in claim 1 wherein said means for supplyingpressurized gas include:

an air compressor; and

an air reservoir connected to receive compressed air from said aircompressor and to supply said compressed air to said valve means.

1. A system for moving cargo in an aircraft having a roller floor, saidsystem including a power shuttle assembly comprised of: a track assemblypositioned longitudinally in the roller floor of the aircraft includinga rack; a dolly assembly adapted to be movable along said trackassembly, said dolly assembly including means for predeterminately,frictionally engaging beneath the cargo which include a plate memberrestrained to limited vertical movement with respect to said dollyassembly, an upwardly facing friction pad on said plate member, and anairbag in position beneath said plate member to raise said plate memberand said friction pad when inflated; and a power unit including meansfor removable attachment to said dolly assembly including means forestablishing pneumatic communication therebetween, a pinion gear forpositive engagement with said track assembly rack, a reversable variablespeed electric motor, an electrical power cable for conductingelectrical energy to said electric motor, means to transfer torquebetween said pinion gear and said electric motor so that said electricmotor can drive said power unit with respect to the aircraft so saiddolly assembly can be controllably moved along said track assembly,means to maintain a predetermined tension on said power cable as saidpower unit moves with respect to the aircraft, means for supplyingpressurized gas, and valve means, said valve means including a solenoidvalve having an inlet port connected to said supply means, an outletport for connection to said airbag and a vent port, said solenoid valvewhen energized being capable of controllably opening a passagewaybetween said inlet port and said outlet port, and controllably opening apassageway between said outlet port and said vent port, said solenoidclosing said outlet port when de-energized. pg,16
 2. The system definedin claim 1 wherein said dolly assembly includes: opposite end portions,each end including said frictional means for extending under the cargoand for controllably frictionally engaging therewith; and a centralportion between said opposite end portions adapted for engagement withsaid power unit.
 3. The system defined in claim 2 wherein said valvemeans include: a manual valve connected to said solenoid valve outputport, said manual valve having a first position for opening a passagewayfrom said solenoid valve output port to said frictional means in one ofsaid opposite end portions, and a second position for opening apassageway from said solenoid valve output port to said frictional meansin the other of said opposite end portions.
 4. The system defined inclaim 1 including: powered rollers positioned in the floor of theaircraft and spaced from said track assembly; control means for saidpowered rollers whereby said powered rollers can be used to move cargoat generally right angles to said track assembly to facilitate lateralmovement of the cargo within the aircraft.
 5. The system defined inclaim 1 including: a remote control device; and an electrical cable forconnecting said remote control device to said power unit so that theoperation of said control unit can be controlled thereby, said remotecontrol device including a directional speed control for said motor anda solenoid valve control.
 6. The system defined in claim 1 wherein saidmeans for supplying pressurized gas include: an air compressor; and anair reservoir connected to receive compressed air from said aircompressor and to supply said compressed air to said valve means.